JPH11128785A - Coating apparatus and method for applying multicolored pattern coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus capable of stably applying a multi-colored pattern coating having good film quality or color tone to an object to be coated over a long period of time. SOLUTION: In a coating apparatus PS for applying a multi-color pattern coating to an object 1 to be coated, paint is supplied from paint storage tanks 7 and 16 to paint supply passages 9 and 18 to a two-liquid concentric coating gun 3 of a coating machine P, respectively. Circulating machines 13 and 21 are provided, and the paint circulating machines 13 and 21 stabilize the paint supply pressure to the two-liquid concentric type coating gun 3, whereby the pumps 10, 19 and 26
The fluctuation of the film quality or the color tone of the multicolored pattern paint caused by the pulsation of the paint is prevented. In this way, a multi-colored pattern with good film quality or color tone can be stably applied to the object 1 over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method for applying a multicolored pattern coating to an object to be coated, and more particularly to stabilizing the film quality or quality of the multicolored pattern coating for a long time. And a coating method.

[0002]

2. Description of the Related Art In general, as a method of applying a multicolored pattern coating to an object to be coated, for example, a pattern coating having an appearance such as a natural stone (marble or the like), paints of a plurality of colors are successively applied by brush coating, spray coating, or the like. A simple method of repainting by using a simple method is widely used. However, such a conventional method has a problem in that the painting operation has to be repeated as many times as the number of colors of the paint to be painted, so that the painting operation is troublesome. In addition, since the upper layer must be painted after the lower layer is dried, the work efficiency is extremely poor and the construction cost is high.

In order to solve such a problem, for example, Japanese Patent Application Laid-Open No. 50-4137 discloses an epoxy resin serving as a base material and a color base obtained by dissolving an incompatible resin in an organic solvent and coloring. And a curing agent have been proposed, in which a multi-color pattern coating is applied in a single coating using a coating obtained by mixing a paint with a curing agent. In this coating method, at the time of coating, the solvent evaporates, while the heat generated by the reaction causes deposition of the color base and convection, and the flow of the precipitate forms a multicolored pattern.

In Japanese Patent Application Laid-Open No. 59-61638, a multi-color paint made of a synthetic resin emulsion adjusted to have a high viscosity so as not to be easily mixed is used, and the inside of the paint gun is partitioned by a partition plate. There has been proposed a coating technique in which a plurality of paints are simultaneously sprayed from a coating gun so that the paints are not mixed with each other, thereby forming a multicolored pattern by separately coating a plurality of paints without mixing each other.

[0005]

However, in the conventional coating method disclosed in Japanese Patent Application Laid-Open No. 50-4137, only a combination of an epoxy resin and a resin incompatible with the epoxy resin is used. Therefore, there is a problem that the usable resin material is limited to an extremely narrow range and lacks versatility. In addition, since the flow state of the color-based precipitate changes depending on the evaporation characteristics of the solvent and the heat generation characteristics due to the reaction, the pattern form greatly changes depending on conditions such as environmental temperature and humidity, and setting or adjustment of conditions for obtaining a desired pattern. However, there is a problem that it is very difficult to form a uniform coating film.

In the conventional coating method disclosed in JP-A-59-61638, a high-viscosity paint must be set in order to prevent a plurality of colors of paint from being mixed with each other. If the viscosity of the paint is high, there is a problem that it is extremely difficult to form a fine pattern or finish the surface to be coated smoothly.
In addition, with a high-viscosity coating material, there is a problem that coating unevenness is likely to occur, and it is difficult to form a uniform pattern over the entire surface to be coated.

Further, in Japanese Patent Application Laid-Open No. 1-293163, a two-liquid concentric type coating gun having an inner nozzle and an outer nozzle concentrically arranged so as to surround the inner nozzle is used for atomization. A coating method has been proposed in which paints of different colors are simultaneously sprayed onto an object from an inner nozzle and an outer nozzle using air to apply a multicolored pattern to the object in one coating. . However, in this coating method, the jetting characteristics of each coating material fluctuate due to the fluctuation or pulsation of the supply pressure of each coating material supplied to the two-liquid concentric coating gun, and a multi-color pattern having stable film quality or color tone for a long time. There is a problem that painting cannot be performed. Further, the specific configuration or operating conditions of the coating apparatus provided with the two-liquid concentric coating gun are not always appropriate, and this also causes the deterioration of the film quality or color tone of the multicolored pattern coating. There is.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is capable of stably coating a multi-color pattern with good film quality or color tone over a long period of time in a simple coating process. It is an object of the present invention to provide a means that can be performed by using the method.

[0009]

According to the present invention, there is provided a coating apparatus for applying a multicolored pattern coating according to the present invention, comprising: (a) an inner nozzle for discharging a first coating material; An outer nozzle which is concentrically disposed so as to surround and discharges the second coating material, and simultaneously sprays the first and second coating materials by atomizing air, thereby to set a predetermined speed (conveyor speed) in a predetermined direction. A) a coating machine equipped with a two-liquid concentric type coating gun for applying multicolored pattern coating to the moving object in
(B) The first paint stored in the first paint storage tank is
A first paint supply system (paint supply path) for supplying the inner nozzle of the two-liquid concentric paint gun by a pump; and (c) a first paint supply system between the first pump and the two-liquid concentric paint gun. A first paint circulating device provided to recirculate a part of the first paint in the first paint supply system to the first paint storage tank; (d)
The second paint, which supplies the second paint stored in the second paint storage tank to the outer nozzle of the two-liquid concentric coating gun by the second pump.
A paint supply system (paint supply path), and (e) a second paint supply system interposed between the second pump and the two-liquid concentric coating gun, and a second paint supply system in the second paint supply system. A second paint circulating device for returning a part of the paint to the second paint storage tank is provided. (F) The distance (gun distance) between the tip of the nozzle of the two-liquid concentric coating gun and the object to be coated is 250. (G) The paint discharge amount of each two-liquid concentric coating gun is set to a predetermined value within a range of 250 to 450 cc / min for both nozzles. The ratio of the paint discharge amount of the nozzle to the paint discharge amount of the outer nozzle is 4: 6 to 6: 4.
(I) the atomization pressure of the two-liquid concentric type coating gun is set to a predetermined value in the range of 0.30 to 0.40 kg / cm ² , and (j) the first and second Each of the second paints has a pigment concentration set to a predetermined value within a range of 6 to 10% by weight, and a viscosity of No. 4 Ford cup (or Iwata cup) set to a predetermined value within a range of 23 to 27 seconds. And
In addition, the paint is characterized in that the thixo-index value (Ti value) at a stirring speed of 6 rpm and 60 rpm is set to a predetermined value within a range of 4.5 to 5.5.

In this coating apparatus, the first paint and the second paint are simultaneously sprayed toward the workpiece from the inner nozzle and the outer nozzle of the two-liquid concentric coating gun using atomizing air. Is done. At this time, a part of the two paints are mixed with each other in an atomized state and adhere to the surface to be coated of the object to form a coating film of an intermediate color or a mixed color. In addition, a part of the first paint and a part of the second paint adhere to the surface of the object to be coated with little mixing with the other paint, respectively, and form a coating film of a specific color. To form That is, in addition to a single color portion of each color paint, an intermediate color or a mixed color portion obtained by mixing both paints is formed on the surface to be coated of the paint, and the number of colors of the supplied paint is formed. A multicolored pattern that is separately applied to the above color portions is formed. That is,
In one coating step, a multicolor pattern composed of a single color portion of each paint and a mixed color portion of both paints can be obtained.

In this coating apparatus, the first paint circulation apparatus and the second paint circulation apparatus respectively
Since the supply pressures of the first and second paints supplied to the two-liquid concentric coating gun are constant, the color tone or quality of the multicolored pattern formed on the object to be coated is stabilized for a long time. That is, even when the multicolor pattern painting is performed for a long time, the color tone of the multicolor pattern does not fluctuate due to the pulsation of the paint supply pressure.

In this coating apparatus, the first and second paints are not special paints but general-purpose paints. In other words, the first and second paints only need to be compatible with each other, and general-purpose paints used for ordinary coating can be used, and general-purpose paints having an abundant number of colors can be used. A variety of color combinations can be realized using paint. In this coating apparatus, since a mixed color portion is formed, it is possible to separately apply to more color portions than the number of colors of the paint used.
In particular, if the mixed color portion is made to be the base coat color, the labor of painting the base coat color in advance and then painting the pattern portion in a separate process as in the conventional painting method is unnecessary, and the painting work Is greatly streamlined.

According to this coating apparatus or coating method,
Basically, the coating can be performed under the same apparatus conditions as in the normal coating method, so that the coating operation is simple and the coating cost is low. In addition, the finish of the multicolored pattern can be adjusted only by changing the coating conditions such as the amount of paint discharged, and a desired finished state can be easily obtained. That is, the painting operation itself can be performed in the same manner as a normal painting method, and is not affected by environmental conditions and the like. Therefore, the painting operation does not require any particular skill, and the painting efficiency is extremely high. In particular, this coating apparatus is suitable for mass coating of interior and exterior surfaces of buildings.

In the above-mentioned coating apparatus, the first paint circulation device is a return passage which branches off from the first paint supply system, connects to the first paint storage tank, and allows the first paint to flow naturally by gravity, and a second paint circulation device. It is preferable that the apparatus is a reflux passage that branches off from the second paint supply system, connects to the second paint storage tank, and allows the second paint to flow naturally by gravity. With this configuration, the supply pressure of the first and second paints supplied to the two-liquid concentric coating gun can be reliably made constant with an extremely simple structure.

Further, the coating method for applying a multicolored pattern coating according to the present invention is characterized in that: (a) an inner nozzle for discharging a first coating and a second coating arranged concentrically so as to surround the inner nozzle. Using a coating machine having a two-liquid concentric coating gun having an outer nozzle that discharges the first and second paints simultaneously by atomizing air, and moves at a predetermined speed in a predetermined direction. A coating method for applying a multi-color pattern coating to an object to be coated, wherein (b) a first paint stored in a paint storage tank is supplied to an inner nozzle of a two-liquid concentric coating gun by a pump, and A part of the first paint in the paint supply system between the two-liquid concentric paint gun is refluxed to the paint storage tank, and (c) the second paint stored in the paint storage tank is subjected to two-liquid pumping. While supplying to the outer nozzle of the concentric paint gun, The second part of the paint in the paint supply within the system between the two-liquid concentric type spray gun to reflux to paint reservoir,
(D) The two-liquid concentric coating gun is arranged such that the distance between the tip of the nozzle and the object to be coated is within a range of 250 to 350 mm, and (e) paint discharge of the two-liquid concentric coating gun. The amount is set within a range of 250 to 450 cc / min for both nozzles, and the ratio of the amount of paint discharged from the inner nozzle to the amount of paint discharged from the outer nozzle is set within a range of 4: 6 to 6: 4.
(F) The atomization pressure of the two-liquid concentric type coating gun is 0.30 to 0.40.
kg / cm ² , (g) the first and second paints each have a pigment concentration within the range of 6 to 10% by weight, and have a No. 4 Ford cup viscosity of 23 to 27.
Seconds and stirring speed of 6 rpm and 60 rpm
thixoindex value in the case of pm is 4.5 to 4.5
It is characterized in that a paint within the range of 5.5 is used. In this coating method, the first paint is returned to the paint storage tank by gravity flowing down naturally in the passage branched from the paint supply system, and the second paint is branched from the paint supply system. It is preferable to return the paint to the paint storage tank by allowing it to flow naturally by gravity in the passage. Also in this coating method, similarly to the case of the coating apparatus according to the present invention, the color tone or quality of the multicolored pattern formed on the object to be coated can be stabilized for a long time. That is, even when the multicolor pattern painting is performed for a long time, the color tone of the multicolor pattern does not fluctuate due to the pulsation of the paint supply pressure.

In the above-described coating apparatus or coating method, a coating machine is provided with a plurality of (for example, four) two-liquid concentric coating guns, and the plurality of two-liquid concentric coating guns are provided in a predetermined direction in the moving direction of the object to be coated. It is preferable to arrange the coating machine at intervals of (gun pitch) and reciprocate the coating machine at a predetermined speed (reciprocating speed) in a direction perpendicular to the moving direction of the object to be coated. in this case,
(A) The arrangement interval (gun pitch) of a plurality of two-liquid concentric coating guns in a coating machine is set to a predetermined value within a range of 130 to 170 mm, and (b) the pattern width of each two-liquid concentric coating gun (coating target) 250-35)
(C) The moving speed (conveyor speed) of the object to be coated is set to a predetermined value within a range of 4.9 to 5.9 m / min. It is preferable that the reciprocating speed (reciprocating speed) is set to a predetermined value within a range of 58 to 68 m / min. This makes it possible to apply a multicolored pattern with better film quality or color tone to the object to be coated.

In the above-mentioned coating machine, an intermediate or mixed color paint obtained by mixing the first paint and the second paint is located upstream of the two-liquid concentric paint gun in the moving direction of the workpiece. May be provided with an airless type coating gun for preliminarily coating the object to be coated. In this way, even when relatively deep irregularities are present on the surface of the object to be coated, a coating film of a neutral color or a mixed color can be reliably and uniformly formed on all surfaces to be coated.

In the above-mentioned coating apparatus or coating method, the thickness of the coating film on the object to be coated is preferably set in the range of 170 to 180 g / m ² . Regarding the color tone of both paints, it is preferable that the first paint is dark (for example, pale gray, beige, etc.) and the second paint is light (for example, gray, white, etc.). In this way, it is possible to apply a multi-color pattern painting with even better film quality or color tone to the object to be coated.

In the above-described coating apparatus or coating method, the supply system of the first paint and the supply system of the second paint are provided with a cleaning device or the like, and are appropriately cleaned with cleaning water and subjected to air purging. preferable. This makes it possible to clean the paint supply system very easily, for example, when changing the type of paint.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. FIG. 1 is a system configuration diagram of a coating apparatus according to the present invention. As shown in FIG. 1, this coating apparatus PS
In FIG. 2, the object 1 is conveyed by the conveyor 2 in a constant direction at a constant speed (conveyor speed) (see FIG. 2). The coating machine P applies a multicolored pattern to the upper surface (surface to be coated) of the object 1 to be coated. The coating machine P is provided with four two-liquid concentric coating guns 3 (see FIGS. 3 to 6) and two airless air conditioning coating guns 4 (see FIG. 2).

Here, the two-component concentric coating gun 3 combines the dark paint introduced into the inner paint supply passage 5 and the light-color paint introduced into the outer paint supply passage 6 as described in detail later.
Each is sprayed from the inner nozzle 70 (see FIG. 6) and the outer nozzle 71 (see FIG. 6) toward the article 1 using atomizing air, so that the article 1 is coated with a multicolored pattern. It has become. On the other hand, the air conditioner coating gun 4 sprays an intermediate color paint, which is a mixture of a dark paint and a light paint at a predetermined ratio, toward the workpiece 1 with the supply liquid pressure without using pressurized air. The object 1 is coated with a uniform intermediate color.

Hereinafter, a paint supply system to the two-component concentric coating gun 3 will be specifically described. First, the light color paint supply system will be described. In this light color paint supply system, basically, the light color paint 8 (for example, gray, white, etc.) stored in the light color paint storage tank 7 is concentric with the two liquids via the light color paint supply passage 9 (9a to 9c). The paint is supplied to the paint supply passage 6 outside the mold coating gun 3. Then, as viewed in the basic flow direction of the light-color paint, the light-color paint supply passage 9a is located slightly downstream of the light-color paint storage tank 7, and the light-color paint 8 in the light-color paint storage tank 7 is pumped up (pumped). A pump 10 is provided. Further, the light-colored paint supply passage 9a is located slightly downstream of the light-colored paint pump 10,
A pulsation buffering volume 11 for suppressing pulsation of the discharge pressure of the light-color paint discharged from the light-color paint pump 10 is provided.

As described above, the pulsation damping volume 11 is provided, and as will be described later, the two-liquid concentric coating gun 3 is used.
The light-color paint circulator 13 is provided to make the light-color paint supply pressure to the light-color paint supply pressure constant.
Various types of pumps can be used. That is,
In addition to a snake pump having a relatively small discharge pressure pulsation, a pump having a relatively large discharge pressure pulsation, such as a diaphragm pump, can be used without any problem. Also,
A gear pump can also be used.

In the light paint supply passage 9 downstream of the pulsation damping volume 11, the light paint supply passage 9 is sequentially connected from the upstream to the outer paint supply passage 6 of the two-liquid concentric coating gun 3 (outside nozzle). A first cleaning device 12 (main cleaning device) for appropriately cleaning the light-color paint supply path up to 71), and a light-color paint circulator for making the supply pressure of the light-color paint supplied to the two-liquid concentric coating gun 3 constant. 13 and mainly 2
A second cleaning device 15 (sub-cleaning device) for appropriately cleaning the outer paint supply passage 6 or the outer nozzle 71 (see FIG. 6) of the liquid concentric coating gun 3 is provided. The first
As will be described later, the cleaning device 12 and the second cleaning device 15 appropriately clean not only the light-color paint supply path but also the dark-color paint supply path.

The light-color paint circulating machine 13 includes a first cleaning device 12
A part (at the time of spraying paint) or all (at the time of stopping paint spraying) of the pale paint flowing through the pale paint supply passage 9b is provided in the pale paint supply passage 9b between the light paint and the second cleaning device 15. The light is returned to the light-colored paint storage tank 7 through the return passage 14 by natural flow. As a result, the supply pressure of the light-color paint to the two-liquid concentric paint gun 3 is made constant.

The first cleaning device 12 has an on-off type air introduction valve 12a for introducing air for purging into the light color paint supply path when cleaning the light color paint supply path.
And an on / off type washing water introduction valve 12b for introducing washing water. Further, the first cleaning device 12 is provided with an on / off type light color paint valve 12c for flowing the light color paint to the downstream side during coating.
Here, at the time of painting, the light paint valve 12c is opened, while the air introduction valve 12a and the washing water introduction valve 12c are opened.
b is closed, and at this time, the light-color paint in the light-color paint supply passage 9a upstream of the first cleaning device 12 flows into the light-color paint supply passage 9b downstream of the first cleaning device 12.

On the other hand, at the time of washing the light color paint supply path, first, the washing water introduction valve 12b is opened, while the air introduction valve 12a and the light color paint valve 12c are closed, and at this time, the light color paint supply downstream of the first cleaning device 12 is performed. The path (the outer paint supply passage 6 or the outer nozzle 71 of the light-color paint supply passage 9b to the two-liquid concentric paint gun 3) is washed with washing water. Thereafter, while the air introduction valve 12a is opened, the washing water introduction valve 12b and the light color paint valve 12c are opened.
Is closed, and at this time, the light paint supply path downstream of the first cleaning device 12 is purged with air, and the cleaning water remaining in the path is discharged. Thus, the first cleaning device 12
The light color paint supply path on the downstream side is cleaned.

The second cleaning device 15 has an on-off port for introducing purge air into the light-color paint supply path when cleaning the two-liquid concentric coating gun 3 (outer paint supply path 6 or outer nozzle 71). Off-type air introduction valve 15a and on / off-type cleaning water introduction valve 15 for introducing cleaning water
b. Further, the second cleaning device 15 is provided with an on / off type light color paint valve 15c for flowing the light color paint to the downstream side at the time of coating. here,
At the time of painting, while the light paint valve 15c is opened, the air introduction valve 15a and the washing water introduction valve 15b are closed, and at this time, the light paint in the light paint supply passage 9b upstream of the second cleaning device 15 is 2 It flows into the light paint supply passage 9c downstream of the cleaning device 15.

On the other hand, at the time of cleaning the two-liquid concentric type paint gun, first, the cleaning water introduction valve 15b is opened, while the air introduction valve 15a and the light color paint valve 15c are closed. The paint supply path (the outer paint supply path 6 or the outer nozzle 71 of the light-color paint supply path 9c to the two-liquid concentric coating gun 3) is washed with washing water. Thereafter, while the air introduction valve 15a is opened, the cleaning water introduction valve 15b and the light paint valve 1 are opened.
5c is closed. At this time, the light-color paint supply path downstream of the second cleaning device 15 is purged with air, and the cleaning water remaining in the path is discharged. Thus, the light paint supply path downstream of the second cleaning device 15 is cleaned.

Next, the dark paint supply system will be described. In this dark color paint supply system, two colors of a first dark color paint (for example, pale gray) and a second dark color paint (for example, beige) are used.
The two types of dark paint can be arbitrarily switched and supplied to the two-liquid concentric coating gun 3. In addition, 3
It goes without saying that more than two kinds of dark paints may be switched and used.

In the dark paint supply system, when the first dark paint is selected, the first dark paint 17 stored in the first dark paint storage tank 16 is transferred to the first dark paint supply passage 18.
(18a to 18c), the liquid is supplied to the inner paint supply passage 5 of the two-liquid concentric paint gun 3. Then, as viewed in the basic flow direction of the first dark color paint, the first dark color paint supply passage 18a is located slightly downstream of the first dark color paint storage tank 16, and the first dark color paint storage tank 16 has the first dark color paint storage tank 16. A first dark color paint pump 19 for pumping up the dark color paint 17 is provided. Further, a little downstream of the first dark color paint pump 19, the first dark color paint supply passage 18a,
As in the case of the light color paint supply system, the pulsation buffering volume 20
Is provided.

The first dark paint supply passage 18a is connected to the first dark paint valve 12f of the first cleaning device 12 on the downstream side of the pulsation buffer volume 20. Further, a first dark paint supply passage 18b downstream of the first cleaning device 12 is connected to the first dark paint valve 15f of the second cleaning device 15. The first dark paint supply passage 18c downstream of the second cleaning device 15
Are connected to the inner paint supply passage 5 of the two-liquid concentric paint gun 3.

When the second dark paint is selected in the dark paint supply system, the second dark paint 24 stored in the second dark paint storage tank 23 is supplied to the second dark paint supply passage 25 by the second dark paint supply passage 25. Through the first dark paint supply passages 18b and 18c,
The two-component concentric coating gun 3 is supplied to an inner coating supply passage 5. Then, as viewed in the basic flow direction of the second dark paint, the second dark paint supply passage 25 is located at a slightly downstream side of the second dark paint storage tank 23. A second dark paint pump 26 for pumping up the dark paint 24 is provided. Further, a pulsation buffering volume 27 is provided in the second dark paint supply passage 25 slightly downstream of the second dark paint pump 26, as in the case of the light paint supply system.

On the downstream side of the pulsation buffering volume 27, the second dark paint supply passage 25 is connected to the second dark paint valve 12g of the first cleaning device 12. The second dark paint supply passage 25 is collected (connected) to the first dark paint supply passage 18b immediately downstream of the second dark paint valve 12g. That is, on the downstream side of the first cleaning device 12, the first dark paint supply passages 18b, 18c
Is used as a common paint supply path for the first dark paint and the second dark paint.

A dark paint circulator 21 is provided in the first dark paint supply passage 18b slightly downstream of the first cleaning device 12. The dark paint circulator 21 transfers a part (at the time of paint ejection) or all (at the time of paint stop) of the first dark paint or the second dark paint flowing through the first dark paint supply passage 18b. Each of the first dark paint return passages 2
Through the second or second dark paint return passage 28, the fluid is returned to the first dark paint storage tank 16 or the second dark paint storage tank 23 by natural flow. As a result, the supply pressure of the first dark paint or the second dark paint to the two-liquid concentric coating gun 3 is reliably stabilized.

As described above, the pulsation damping volumes 20 and 27 are provided in the dark paint supply path, and the dark paint circulation for keeping the supply pressure of the dark paint to the two-liquid concentric paint gun 3 constant. Since the machine 21 is provided, various types of pumps can be used as the first dark paint pump 19 or the second dark paint pump 26 as in the case of the light paint supply system.

The first cleaning device 12 includes an on-off type air introduction valve 12d for introducing purge air into the dark paint supply path when cleaning the dark paint supply path. An on / off type washing water introduction valve 12e for introducing washing water is provided. Further, the first cleaning device 12 is provided with an on-off type first and second off-color type first paint for introducing a first dark paint and a second dark paint, respectively, at the time of painting.
A dark paint valve 12f and a second dark paint valve 12g are provided. Here, at the time of painting, one of the two dark paint valves 12f and 12g is opened according to the type of the selected dark paint, and the other dark paint valve 1 is opened.
2f (12g), the air introduction valve 12d, and the cleaning water introduction valve 12e are closed, and at this time, the first dark paint supply passage 18a or the second dark paint supply passage 25 in the upstream side of the first washing device 12 is provided. The dark paint flows into the first dark paint supply passage 18b downstream of the first cleaning device 12. On the other hand, at the time of cleaning the dark color paint supply path, similarly to the case of cleaning the light color paint supply path, the dark color paint supply path is cleaned with cleaning water and then air purged.

The second cleaning device 15 includes a two-liquid concentric coating gun 3 (inner paint supply passage 5 or inner nozzle 70).
An on / off air introduction valve 15d for introducing air for purging into the dark paint supply path when
An on / off type washing water introduction valve 15e for introducing washing water is provided. Further, the second cleaning device 1
5 is an on / off switch for flowing the dark paint to the downstream side during painting.
An off-type dark paint valve 15f is provided. Here, while painting, the dark paint valve 15f is opened,
The air introduction valve 15d and the washing water introduction valve 15e are closed. At this time, the dark paint in the first dark paint supply passage 18b upstream of the second washing device 15 is located downstream of the second washing device 15. It flows into the first dark paint supply passage 18c. On the other hand, at the time of cleaning the two-liquid concentric type coating gun, similarly to the case of cleaning the light-colored paint supply path, the dark-colored paint supply path downstream of the second cleaning device 15 is cleaned with cleaning water and then air purged.

As described above, in the paint supply system to the two-liquid concentric coating gun 3, the supply pressure of the light-color paint and the dark-color paint supplied to the two-liquid concentric coating gun 3 is constant, so The color tone or quality of the multicolored pattern formed on the coating 1 is stabilized for a long time. That is, even if the coating is applied for a long time, the color tone of the multicolored pattern does not change due to the pulsation of the paint supply pressure.

Hereinafter, the intermediate color paint supply system for supplying the intermediate color paint to the air conditioner coating gun 4 will be specifically described. In this intermediate color paint supply system, the light color paint 30 (for example, gray) stored in the light color paint tank 29 and the dark color paint 35 (for example, beige) stored in the dark color paint tank 34 are in the paint supply path. To produce an intermediate color paint, which is supplied to the air-conditioning coating gun 4 at a relatively high pressure, and then jetted toward the object 1 with the liquid pressure of the intermediate color paint itself.

Specifically, the light-colored paint 30 in the light-colored paint tank 29 is supplied to the paint mixing / washing device 33 through the light-colored paint passage 32 by the light-colored paint pump 31, while the light-colored paint in the dark-colored paint tank 34 is supplied. The dark paint 35 is supplied by a dark paint pump 36 to a paint mixing / washing device 33 via a dark paint passage 37. Here, a plunger pump is usually used as the light paint pump 31 or the dark paint pump 36 because a high discharge pressure is required.

When cleaning the intermediate color paint supply path, the paint mixing / washing device 33 includes an on / off type air introduction valve 33a for introducing air for purging into the intermediate color paint supply path, and a cleaning water. An on / off type washing water introduction valve 33b for introducing the washing water is provided. Further, the paint mixing / washing device 33 is provided with an on / off type light paint valve 33c and a dark paint valve 33d for introducing a light paint and a dark paint, respectively, at the time of painting. Here, during painting, the light paint valve 33c and the dark paint valve 33d are opened, while the air introduction valve 33a and the washing water introduction valve 33b are closed. At this time, the light paint and the dark paint passage 3 in the light paint passage 32
The dark paint in 7 is introduced into the paint mixing / washing device 33 and mixed therewith, becomes an intermediate paint, flows into the intermediate paint supply passage 38, and is thereafter supplied to the air conditioning paint gun 4.

On the other hand, when cleaning the intermediate color paint supply path, first, the cleaning water introduction valve 33b is opened, while the air introduction valve 33a and both paint valves 33c and 33d are closed, so that the intermediate color paint supply path (the intermediate color paint supply paths 38 to 38) is closed. The air conditioning paint gun 4) is washed by the washing water.
Thereafter, while the air introduction valve 33a is opened, the cleaning water introduction valve 33b and both the paint valves 33c and 33d are closed, the intermediate color paint supply path is air purged, and the cleaning water remaining in the path is discharged. You. In this way, the intermediate color paint supply path is cleaned.

Hereinafter, a specific structure of the coating machine P will be described. As shown in FIG. 2, in the coating machine P, the elongated coating gun support member 40 is elongated in the conveying direction of the conveyor 2, that is, the flow direction or the moving direction of the workpiece 1 as indicated by an arrow Y. Are located. The coating gun support member 40 includes two air conditioning coating guns 4 and four two-liquid concentric coating guns 3 in order from the upstream side to the downstream side as viewed in the flow direction of the workpiece 1. ,Each,
The nozzles are arranged at predetermined intervals (gun pitch) such that the nozzle tips face the object to be coated, that is, downward.

In the coating machine P, the coating gun supporting member 40 is moved in the direction perpendicular to the flow direction or the moving direction of the workpiece 1 as indicated by arrows X ₁ and X ₂ , that is, 1 reciprocate at a predetermined speed (reciprocating speed) in the width direction. Here, the coating gun support member 40 is configured to reciprocate generally between one end and the other end in the width direction of the workpiece 1.

Therefore, when the object 1 moves at a constant speed (conveyor speed) in the Y direction, the object 1
First, painting with an intermediate color paint (first coat painting) is performed by the air conditioner painting gun 4, and a multi-color pattern painting is performed thereon by the two-liquid concentric painting gun 3.
The mechanism of forming the coating film of the multicolored pattern by the two-liquid concentric coating gun 3 and the details such as specific dimensions and operating conditions of the coating machine P will be described later. As described above, since the two-color air-conditioning coating guns 4 apply the intermediate-color pre-coating, even if there are relatively deep irregularities on the surface of the object 1 to be coated, it is possible to surely and entirely cover the entire surface to be coated. A neutral color coating (base coat) is applied evenly.

Hereinafter, the specific structure of the two-liquid concentric coating gun 3 will be described. As shown in FIGS. 3 and 4, the two-liquid concentric type coating gun 3 has an air cap set 45 for spraying atomizing air for atomizing the paint, a paint nozzle set 46 for discharging the paint, and an air A tip body set 47 that supports or holds the cap set 45 and the paint nozzle set 46 and a tip needle valve set 48 that opens and closes the paint nozzle set 46 are provided. The clearance between the tip body set 47 and the tip needle valve set 48 is sealed at a predetermined position by a packing case push 49 and a packing case set 50.
The tip body set 47 is provided with a disk spring 51.

The tip body set 47 includes a body set 53
Attached to. In the main body set 53, there are provided a pattern adjusting device 52 for adjusting the pattern of the multicolored pattern by changing the injection characteristics of the atomizing air, and an air sheet set 54. Further, the main body set 53 is provided with a piston set 55, a needle set 56, a piston pressing spring 57, and a needle spring 58 in order to operate the tip needle valve set 48. Further, at the rear end of the main body set 53, there is provided a paint adjusting device 60 which adjusts the amount of paint discharged by turning the paint adjusting knob 59.

The main body set 53 includes a first air nipple 68 for introducing atomizing air from the atomizing air supply passage 41 (see FIG. 1) to the two-liquid concentric type coating gun 3, and a cylinder air supply. From the passage 42 (see FIG. 1), the piston set 55 and the needle set 5
6 and a second air nipple 69 for introducing cylinder air for driving the tip needle valve set 48 (that is, for opening and closing the paint nozzle set 46). In addition, the main body set 53 includes two bolt sets 61 and 62 for fixing the main body set 53 to the coating gun support member, a connecting rod 63 for connecting the tip needle valve set 48 and the needle set 56, and a needle. A valve packing set 64 and a protective cover 65 are provided.

Then, the two-liquid concentric coating gun 3 includes:
A first paint nipple 66 for introducing a dark paint from the first dark paint supply passage 18c (see FIG. 1) to the inner paint supply passage 5, and an outer paint supply passage from the light paint supply passage 9c (see FIG. 1). 6 is provided with a second paint nipple 67 for introducing a light paint. Here, when cylinder air (tip needle valve set driving air) is introduced into the two-liquid concentric type coating gun 3 from the cylinder air supply passage 41 (see FIG. 1) via the second air nipple 69, the tip needle valve set 48 is retracted and the paint nozzle set 46
Is opened. At this time, first, the inner nozzle 70 communicating with the inner paint supply passage 5 is opened, and then the outer nozzle 71 communicating with the outer paint supply passage 6 is opened (see FIG. 6). Thus, the dark paint in the inner paint supply passage 5 is
The light paint in the outer paint supply path 6 is discharged to the outside from the outer nozzle 71 (see FIG. 6).

When the paint nozzle set 46 is opened as described above, and the dark paint and the light paint are discharged from the inner nozzle 70 and the outer nozzle 71, respectively, the first
Via the air nipple, the atomizing air supply passage 41 (see FIG. 1) is connected to the atomizing air supply passage 74 in the two-liquid concentric coating gun 3.
Is atomized, and the atomized air is ejected from a spray air supply nozzle 72 and an auxiliary air supply nozzle 73 to the outside. Thus, the inner nozzle 70 and the outer nozzle 71
Are sprayed by the atomizing air sprayed from the spray air supply nozzle 72 and the auxiliary air supply nozzle 73, and thereafter are sprayed on the article 1 to be coated. Thereby, as described later, the multi-color pattern is applied to the article 1 to be coated.

The typical specifications of the two-component concentric coating gun 3 used in the coating apparatus according to the present invention will be described below. (Specifications of two-liquid concentric type coating gun) Inner nozzle diameter: 1.0 mmφ Outer nozzle diameter: 2.0 mmφ Maximum working pressure: 7 kgf / cm ² Standard spray pressure: 3 kgf / cm ² Working air volume: 360 ml / min Pressure: 0.5 to 2.0 kgf / cm ² Pattern opening: 250 mm Wetted part material: Stainless steel and aluminum Wetted seal part: Solvent resistant packing Hose connection part: G1 / 4B Weight: 850 g Dimensions: 211 × 95 × 42 [mm]

Hereinafter, a more detailed structure of the two-component concentric coating gun 3 and the mechanism by which the two-component concentric coating gun 3 forms a multicolored coating film will be described. FIGS. 5 to 7 schematically show the structure near the tip (near the nozzle) of the two-liquid concentric coating gun 3 shown in FIGS. 3 and 4 that can apply the coating of the multicolored pattern. The basic structure of the two-liquid concentric type coating gun 3 is the same as that of an ordinary air spray gun or the like, but as described above, the dark paint and the light paint are simultaneously discharged.

More specifically, as shown in FIG. 5 to FIG. 7, an inner nozzle 70 for discharging the dark paint and an outer nozzle 71 formed so as to surround the inner nozzle 70 and discharge the light paint are concentric circles. They are arranged adjacent to each other. And the inner nozzle 70 and the outer nozzle 71 are respectively
The inner paint supply passage 5 and the outer paint supply passage 6 which are separated from each other communicate with each other. As described above, the dark paint and the light paint are supplied to the inner paint supply passage 5 and the outer paint supply passage 6 via the first dark paint supply passage 18 and the light paint supply passage 9, respectively. The dark paint supply path and the light paint supply path to the two-liquid concentric type coating gun 3 are provided with a discharge amount measuring device (not shown) capable of measuring the supply amount, that is, the discharge amount of the dark paint and the light paint, respectively. Is attached.

A concentric spray air supply nozzle 72 is arranged outside the inner nozzle 70 and the outer nozzle 71 so as to surround them. A pair of auxiliary air supply nozzles 73 is provided at a position slightly away from the spray air supply nozzle 72. These auxiliary air supply nozzles 73 inject air in a direction that intersects the air injection direction of the spray air supply nozzle 72. Thus, the spray pattern of the paint that is circular only with the spray air supply nozzle 72 becomes an elongated elliptical spray pattern. As described above, the first air nipple 68 (FIG. 3) is connected to the spray air supply nozzle 72 and the auxiliary air supply nozzle 73.
Atomized air is supplied from a pressurized air supply source (not shown) such as an air compressor via an atomized air atomizing air supply path 74 through an atomizing air supply path 74.

As described above, in the two-liquid concentric coating gun 3, the inner nozzle 70 and the outer nozzle 71 are arranged concentrically, whereby the dark paint and the light paint are simultaneously and uniformly sprayed. And, in such a spraying state, both of the paints are mixed well and surely with each other, so that this structure is very preferable in forming a uniform multicolored pattern.

Hereinafter, a coating method using the two-component concentric coating gun 3 and a mechanism for forming a multicolored coating film, for example, a natural stone-like pattern in the coating will be described. As schematically shown in FIG. 7, in such a coating, a dark paint is jetted from the inner nozzle 70 of the two-liquid concentric paint gun 3, and the dark paint is fine dark paint particles 75a (see FIG. 8). )
Becomes At the same time, the light color paint is ejected from the outer nozzle 71, and the light color paint becomes fine light color paint particles 75b (see FIG. 8). Then, as shown in FIG. 8, a large number of fine dark-colored paint particles 75a and a large number of fine light-colored paint particles 75b are respectively randomly stacked and adhered to the surface of the article 1 (see FIG. 1). Thus, a coating film 75 is formed.
In the coating film 75, a portion where the dark paint particles 75a are intensively stacked has almost the same color tone as the dark paint. The portion where the light-color paint particles 75b are intensively stacked has almost the same color tone as the light-color paint.

However, in the coating film 75, the majority of the portion where the dark paint particles 75a and the light paint particles 75b are appropriately mixed and occupied is occupied, and this portion has an intermediate color between the dark paint and the light paint. Becomes Then, in such an intermediate color portion, the color tone becomes a pattern tone having a different lightness depending on the mixed form of the paint particles 75a and 75b. For example, as shown in FIG. 9, it is assumed that three light-colored paint particles 75 b are attached to the upper or lower side of the paint layer composed of the dark-colored paint particles 75 a while partially overlapping on the coating film 75. . In this case, the regions R _{1 to} R ₃ where the light color paint particles 75 b do not overlap, that is, one light color paint particle 7
The region where only 5b is attached to the dark paint layer has a low lightness color tone. Then, two regions R ₄ to R ₅ to light-colored paint particles 75b are overlapped becomes higher intermediate brightness tones of brightness than area R ₁ to R _3. The region R ₇ which overlap each other three light-colored paint particles 75b will be more high brightness color. That is, in this case, on the coating film 75 includes an area R ₁ to R ₃ of low lightness colors, a region R ₄ to R ₆ of intermediate brightness of the color, and the area R ₇ in high lightness tones A randomly scattered pattern is formed. Note that, in such a pattern based on an intermediate color, there are a small amount of a dark-colored portion substantially composed only of a dark color paint and a light-colored portion substantially composed of only a light-colored paint. Here, various patterns can be formed by preferably adjusting the degree of mixing of the dark paint particles 75a and the light paint particles 75b. For example, a black pattern portion, a halftone pattern portion, and a whitish pattern portion are included. It is possible to express mixed natural stone-like patterns.

Hereinafter, matters to be noted when setting various coating conditions in coating with the two-liquid concentric coating gun 3 will be described. By changing the pressure of the atomizing air (atomizing pressure or atomizing air pressure) among the coating conditions, the mixing ratio of the dark color paint and the light color paint, that is, the single color portion formed on the surface to be coated of the workpiece 1 The ratio with the mixed color portion can be changed. In this case, when the atomization pressure is too high, the two paints are mixed excessively, so that a single color portion is not sufficiently formed, and a multicolored pattern is not easily formed. Conversely, if the atomization pressure is too low, both paints are hardly mixed,
The mixed color portion, that is, the base coat color portion is not sufficiently formed. In consideration of such points, the atomization pressure is set to an appropriate value in accordance with the required finish state of the multicolor pattern. The preferred atomization pressure is as described below.

Viscosity (paint viscosity) of dark paint and light paint
Also, the ratio between the single color portion and the mixed color portion formed on the surface to be coated of the workpiece 1 changes, and if the viscosity is too low, the two paints are mixed too much, making it difficult to form a multicolored pattern. On the other hand, if the viscosity is too high, the mixing of both paints becomes insufficient, and it is difficult to form a mixed color portion. Thus, the viscosity of both paints is set to an appropriate value in consideration of such circumstances. The preferred viscosities of the dark paint and the light paint are as described below.

The discharge amount of the dark color paint and the light color paint affects the finish of the coating film. If the discharge amount is too large, the fineness of the sprayed paint is easily impaired, and the smoothness of the surface to be coated is reduced. As a result, the finished appearance tends to be poor. On the other hand, when the discharge amount is too small, the coating efficiency becomes poor and the productivity is reduced. Thus, the discharge amounts of the dark paint and the light paint are set to appropriate values in consideration of these circumstances. The preferred viscosities of the dark paint and the light paint are as described below.

The finish of the multicolored pattern also affects the overall discharge amount, that is, the ratio of the discharge amount of each paint to the total discharge amount of the inner nozzle 70 and the outer nozzle (hereinafter simply referred to as “discharge amount ratio”). For example, in the case of applying a multi-color pattern painting in which a single color portion is partially formed as a pattern on a base coat color composed of a mixed color, the larger the difference between the discharge amounts of the two paints,
The base coat color is closer to the color of the paint having the larger ejection amount, and the contrast with the pattern of each single color portion is weakened. In particular, if the difference between the discharge amounts is too large, it is difficult to control the adjustment of the discharge amount, the finish is not so different from that of a single color coating, and it is difficult to form a multicolored pattern. vice versa,
If the difference in the ejection amount is small, the base coat color will be a color tone of an intermediate level between the two colored paints, and the contrast with both colors will be strong. Therefore, even with the same combination of paints, the finish of the multicolored pattern greatly changes depending on the discharge amount ratio. The discharge amount ratio can be adjusted to a desired discharge amount ratio by measuring the discharge amount of each paint with a discharge amount measuring device. Note that the preferable discharge amount ratio is as described below.

Hereinafter, matters to be considered when selecting the properties of the paint used for coating with the two-liquid concentric coating gun 3 will be described. As the dark color paint and the light color paint used in the coating apparatus PS, it is only necessary that they can be mixed with each other, and ordinary coloring in which the necessary color pigment is dispersed in an appropriate dispersion medium (solvent) is used. Paint can be used. However, it is preferable that the paint is basically a liquid having a relatively low viscosity so that the paints can be mixed with each other.

Specific coloring pigments include titanium oxide,
Use inorganic pigments such as carbon black, cadmium red, red iron oxide, molybdenum red, iron oxide, cadmium yellow, graphite, ultramarine and navy blue, or organic pigments such as azo pigments, nitro pigments, lake pigments and phthalocyanine pigments be able to.

A plurality of colors having different colors are selected from the above-mentioned colored paints and used in combination. As a method of combining the color paints, any one of a combination based on a difference in color difference, a combination based on a difference in hue, a combination based on a difference in lightness, or a combination based on a difference based on a plurality of different attributes is used. be able to.

For example, a combination of white and black can be considered as the magnitude of the color difference. As the color difference increases, a stronger contrast occurs in the finish. A combination of pink and sky blue may be considered as a combination having the same lightness and different hue. In this case, a strong contrast due to the hue difference occurs. As a combination having the same hue and different lightness, a combination of pink and red can be considered.
In this case, since the contrast is based on the difference in brightness, the finished multicolored pattern paint has a unique appearance such that the paint looks like a single color at a distance and the pattern can be seen from a close distance.

Hereinafter, based on the above considerations and the like,
Preferred specifications and operating conditions of the coating apparatus PS or the coating machine P will be specifically described. Preferred specifications or operating conditions of the coating machine P are as follows. (Preferable specifications of coating machine, etc.) 1. Gun distance h 250-350mm Reciprocating speed 58-68m / min 3. Conveyor speed 4.9-5.9m / min4. 4. Pattern width w 250 to 350 mm 5. Total discharge (1 gun) 250-450 cc / min 6. Discharge amount ratio 4: 6 to 6: 4 7. Gun pitch p 130-170mm Atomization pressure 0.30-0.40 kg / cm ²

FIG. 10 schematically shows the gun distance h, the pattern width w, and the gun pitch p in the above specification. In FIG. 10, a paint spray 7 sprayed from two adjacent two-liquid concentric paint guns 3 onto the work 1 is shown.
No. 6 overlaps in the range shown by d. This is because the paint spray 76 has the highest paint density at the center of the pattern (immediately below the nozzle), and the paint density becomes lower toward the periphery, so that adjacent paint sprays 76 overlap to some extent, This is to make the amount of paint adhered to the object 1 uniform.

Preferred specifications of the dark color paint and the light color paint are as follows. (Preferable specifications of paint) Viscosity 23-27 seconds: No. 4 Ford Cup 2. 2. Pigment concentration 6 to 10% by weight 3. Ti value 4.5 to 5.5 170-180 g / m ²

FIG. 11 is a graph showing the results of measuring the color difference (ΔL and ΔE) of the coating film while changing the paint viscosity. FIG. 12 is a graph showing the color difference (ΔL and ΔE) of the coating film while changing the atomizing pressure. 4) is a graph showing the result of the measurement. In such a multicolored pattern coating, generally, the color difference ΔE is approximately 1.
A value of 5 or less is considered aesthetically preferable. As described above, in the coating apparatus PS, the paint viscosity is set to 23 to 27 seconds, but in the paint viscosity in this range, according to FIG. 11, the color difference ΔE is 1.5 or slightly higher than this. Therefore, it is understood that setting the paint viscosity in this manner is preferable from the viewpoint of aesthetics of the multicolored pattern paint.

As described above, in this coating apparatus PS, the atomization pressure is set to 0.30 to 0.40 kg / cm ² , but in the atomization pressure in this range, according to FIG. The color difference ΔE is equal to or less than 1.0, and thus, it is understood that setting the atomization pressure in this manner is preferable from the viewpoint of aesthetics of the multicolor pattern painting.

As described above, according to the coating apparatus PS of the present invention, it is possible to stably apply the multicolored pattern having good film quality or color tone to the object 1 in a simple coating process over a long period of time.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a coating apparatus according to the present invention.

FIG. 2 is a perspective view schematically showing a coating machine used in the coating apparatus shown in FIG.

FIG. 3 is a partial cross-sectional front view of a two-liquid concentric coating gun.

FIG. 4 is a plan view of the two-liquid concentric coating gun shown in FIG.

FIG. 5 is a bottom view schematically showing the tip of the two-liquid concentric coating gun shown in FIG. 3;

FIG. 6 is a sectional view taken along line AA of the two-liquid concentric coating gun shown in FIG. 5;

FIG. 7 is a diagram schematically showing the flow of paint and air in a nozzle portion of the two-liquid concentric coating gun shown in FIG.

FIG. 8 is a perspective view schematically showing a coating film formed on the surface of an object to be coated and including dark paint particles and light paint particles.

9 is a diagram schematically showing a mixed form of a dark paint and a light paint in a portion surrounded by a circle A of the coating film shown in FIG. 8;

FIG. 10 is a view schematically showing an arrangement of a two-liquid concentric coating gun of a coating machine.

FIG. 11 is a graph showing the dependence of the color difference of the multicolored pattern coating film on the paint viscosity.

FIG. 12 is a graph showing the dependence of the color difference of the multicolored pattern coating film on the atomization pressure.

[Explanation of symbols]

PS: coating apparatus, P: coating machine, 1: object to be coated, 2: conveyor, 3: two-liquid concentric coating gun, 4: air conditioning coating gun, 5: inner paint supply path, 6: outer paint supply path, 7 ... Light color paint storage tank, 8 ... Light color paint, 9 (9a-9c) ... Light color paint supply passage, 10 ... Light color paint pump, 11 ... Pulsation buffer capacity part, 12 ... First cleaning device, 13 ... Light color paint circulation machine , 14 ... light paint return path, 15 ... second washing device, 1
6 ... First dark paint storage tank, 17 ... First dark paint, 18 (1
8a to 18c): First dark paint supply passage, 19: First dark paint pump, 20: Pulsation buffering volume, 21: Dark paint circulator, 22: First dark paint return passage, 23 ... second
Dark paint storage tank, 24: second dark paint, 25: second dark paint supply passage, 26: pump for second dark paint, 27: pulsation buffer volume, 28: second dark paint return passage , 29 ... Light color paint tank, 30 ... Light color paint, 31 ... Light color paint pump, 32 ... Light color paint passage, 33 ... Paint mixing / washing device,
34: dark paint tank, 35: dark paint, 36: dark paint pump, 37: dark paint passage, 38: intermediate paint supply passage, 40: paint gun support member, 41: atomizing air supply passage, 42 ... Cylinder air supply passage, 70 ... Inner nozzle,
71: outside nozzle, 72: spray air supply nozzle, 73 ...
Auxiliary air supply nozzle, 74: atomizing air supply path, 75: coating film, 75a: dark paint particles, 75b: light paint particles, 7
6 Paint spraying.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidetoshi Suzuki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Kaoru Yoshihara 4-44-3 Miyugaoka, Aoba-ku, Yokohama-shi, Kanagawa-ken (72 Inventor Keizo Ikemoto 19-17 Ikedanakacho, Neyagawa-shi, Osaka Japan Paint Co., Ltd. (72) Inventor Koji Koizumi 19-17 Ikedananakacho, Neyagawa-shi, Osaka Japan Paint Co., Ltd.

Claims (16)

[Claims] An inner nozzle for discharging a first paint, and a second inner nozzle arranged concentrically so as to surround the inner nozzle.
An outer nozzle for discharging the first paint and the second paint at the same time by spraying the first and second paints by the atomizing air to apply a multicolored pattern painting to the workpiece moving at a predetermined speed in a predetermined direction. A coating machine provided with a liquid concentric coating gun, and a first pump for supplying the first coating material stored in the first coating tank to an inner nozzle of the two-liquid concentric coating gun by a first pump.
A paint supply system, and a first pump between the first pump and the two-liquid concentric coating gun.
The first paint supply system is provided in the paint supply system.
A first paint circulating device that refluxes a part of the paint in the first paint tank, and a second paint that is stored in the second paint tank is supplied to the outer nozzle of the two-liquid concentric coating gun by the second pump. Second
A paint supply system, and a second pump between the second pump and the two-liquid concentric coating gun.
The second paint supply system is provided in the paint supply system.
And a second paint circulation device for returning a part of the paint to the second paint storage tank, wherein the two-liquid concentric coating gun has a distance between the tip of the nozzle and the object to be coated of 250 to 350 mm. The paint discharge rate of the two-liquid concentric coating gun is set within a range of 250 to 450 cc / min for both nozzles, and the paint discharge rate of the inner nozzle and the paint discharge rate of the outer nozzle. The ratio of the paint discharge amount is set within the range of 4: 6 to 6: 4, and the atomization pressure of the two-liquid concentric coating gun is 0.30 to 0.40 kg / cm.
² , and the first and second paints each have a pigment concentration within a range of 6 to 10% by weight, and a No. 4 Ford cup viscosity within a range of 23 to 27 seconds. A coating apparatus for applying a multicolored pattern coating, wherein the coating composition has a thixoindex value in the range of 4.5 to 5.5 when the stirring speed is 6 rpm and 60 rpm. 2. The first paint circulation device is a reflux passage that branches off from a first paint supply system and is connected to a first paint storage tank, and allows the first paint to flow naturally by gravity. A multi-color pattern coating according to claim 1, characterized in that it is a return passage which branches off from the second paint supply system, connects to the second paint storage tank, and allows the second paint to flow naturally by gravity. Coating equipment to be applied. 3. The coating machine is provided with a plurality of two-liquid concentric coating guns, and the plurality of two-liquid concentric coating guns are arranged at predetermined intervals in a moving direction of the object to be coated, and The multi-color pattern coating according to claim 1 or 2, wherein the coating machine reciprocates at a predetermined speed in a direction perpendicular to the moving direction of the object to be coated. Painting equipment. 4. An arrangement interval of a plurality of two-liquid concentric coating guns in the coating machine is in a range of 130 to 170 mm, and a pattern width of each two-liquid concentric coating gun is 250 to 170 mm.
The moving speed of the object is within a range of 4.9 to 5.9 m / min, and the reciprocating moving speed of the coating machine is 58 to 68 m / min.
The coating apparatus for applying a multicolored pattern coating according to claim 3, wherein the coating is within the range of minutes. 5. The apparatus according to claim 1, wherein said coating machine is provided with
An airless type coating gun is provided upstream of the liquid concentric type coating gun to preliminarily apply a mixed color paint obtained by mixing the first paint and the second paint to the object to be coated. A coating apparatus for applying the multicolored pattern coating according to claim 3 or 4. 6. The multicolored pattern according to claim 1, wherein the first paint is a dark paint, and the second paint is a light paint. Painting equipment for painting. 7. A film thickness of a coating film of an object to be coated is 170 to 180 g.
/ M, characterized in that it is in the range of ^2, the coating apparatus for applying a polychrome pattern painted as set forth in claim 6. 8. The cleaning apparatus according to claim 1, further comprising a cleaning device that cleans the first paint supply system and the second paint supply system with cleaning water and performs air purging. Coating equipment for applying the multicolored pattern coating described in (1). 9. An inner nozzle for discharging a first paint and a second nozzle concentrically disposed so as to surround the inner nozzle.
Using a coating machine equipped with a two-liquid concentric type coating gun having an outer nozzle for discharging the coating material, the first and second coating materials are simultaneously sprayed by atomizing air at a predetermined speed in a predetermined direction. A coating method for applying a multicolored pattern coating to a moving object to be coated, wherein a first paint stored in a paint storage tank is supplied to an inner nozzle of a two-liquid concentric coating gun by a pump, and the pump and the above A part of the first paint in the paint supply system between the two-liquid concentric paint gun and the second paint is returned to the paint tank, and the second paint stored in the paint tank is pumped by the two-liquid concentric paint gun. A part of the second paint in the paint supply system between the pump and the two-liquid concentric paint gun is returned to the paint storage tank, and the two-liquid concentric paint gun is The distance between the tip of the nozzle and the object to be coated is 250 to 350 mm It arranged to be within the scope, and sets the range of 250～450Cc / min paint discharge amount in both nozzle sum of the two-liquid concentric type spray gun,
The ratio of the amount of paint discharged from the inner nozzle to the amount of paint discharged from the outer nozzle is set in the range of 4: 6 to 6: 4, and the atomizing pressure of the two-liquid concentric coating gun is 0.30 to 0.40 kg /. set within the range of cm ^2, and, respectively as the first and second coating material, the pigment concentration is in the range of 6-10% by weight, in the range viscosity by No. 4 Ford cup is 23 to 27 seconds And a paint having a thixotropic index value in the range of 4.5 to 5.5 when the stirring speed is 6 rpm and 60 rpm. 10. The first paint is returned to a paint storage tank by gravity flow in a passage branched from the paint supply system by gravity, and the second paint is branched from the paint supply system. The method for applying a multicolored pattern according to claim 9, wherein the paint is returned to the paint storage tank by causing the inside of the passage to flow naturally by gravity. 11. A plurality of two-liquid concentric coating guns are provided in the coating machine, and the plurality of two-liquid concentric coating guns are arranged at predetermined intervals in a moving direction of an object to be coated. The coating method for applying a multicolored pattern coating according to claim 9 or 10, wherein the machine is reciprocated at a predetermined speed in a direction perpendicular to the moving direction of the object to be coated. 12. The arrangement interval of a plurality of two-liquid concentric coating guns in the coating machine is set within a range of 130 to 170 mm, and the pattern width of each two-liquid concentric coating gun is set to 250.
The moving speed of the object to be coated is set within a range of 4.9 to 5.9 m / min, and the reciprocating speed of the coating machine is set to 58 to 68 m.
12. The method according to claim 11, wherein the value is set within a range of / min.
The method of applying the multi-color pattern painting described in. 13. An airless coating gun is provided in the coating machine upstream of the two-liquid concentric coating gun when viewed in the moving direction of the object to be coated, and the first coating material and the second coating material are separated by the coating gun. The coating method for applying a multicolored pattern coating according to claim 11 or 12, wherein the mixed color paint that has been mixed is preliminarily applied to an object to be coated. 14. The multicolor pattern according to claim 9, wherein a dark paint is used as the first paint, and a light paint is used as the second paint. A painting method to apply painting. 15. The film thickness of a coating material to be coated is from 170 to 180.
and setting in the range of g / m ^2, coating method of applying a polychrome patterns painted according to claim 14. 16. A supply system for the first paint and the second paint supply system.
The coating method for applying a multicolored pattern coating according to any one of claims 9 to 15, wherein the paint supply system is appropriately cleaned with cleaning water and subjected to air purging.